Fillers are used in the wood industry, particularly in construction and in the furniture industry, in order to repair the wood where it has cracked, where it has been necessary to drill holes or the like during the fabrication process, or in the repair of damage to the wood product. The demands on the product properties for such fillers when the wood is to be painted are not high, provided that a smooth surface can be obtained. However, when the wood must retain its natural beauty e.g. it is to be stained so as to show its natural grain, the requirements on the filler are substantially more demanding. In the latter case, it becomes very important that the filler be able to match the color of the wood, including after any staining, so that it is not readily apparent that a filler has been used on the wood.
Fillers on the marker that are intended for use with wood tend to be of a type generally known as a plastic wood which often are products that are both potentially toxic to persons using the product and highly flammable. As these products are used indoors, there is a potential hazard to persons who suffer from, for example, allergies, and in any event the odors e.g. from solvents, associated with use of the product tend to be obnoxious to persons working with the product. Moreover, plastic wood becomes very hard when it has set, and it must be sanded down where needed. This is a labour intensive process, and a process that is difficult on shaped mouldings. Plastic wood tends to shrink on drying, making it susceptible to separation or falling out of the hole that it has filled. In addition, plastic wood tends to come in pre-determined colors, which must be purchased specifically for the intended use. Plastic wood is generally regarded as not accepting stain, tending to remain substantially the original colour if staining is attempted. Consequently, it is difficult to select an amount of filler that is appropriate for the particular job requiring repair, with the result that part of the filler usually has to be discarded, and plastic wood tends to be unpleasant to work with.
One of the methods of coloring fillers currently available is to use a colored crayon, which is an oil-based product. The oil content within the crayon often results in staining of the wood around where the filler has been used, leaving a distinct mark such that the location of where the filler was used is apparent. Moreover, as illustrated hereinafter, during use of plastic wood to fill a hole, it is normally necessary to use a tool to force the plastic wood into the hole and smooth the surface. This leaves an area around the hole that is difficult to stain, due to contact with the plastic wood, even after attempts to clean and sand the area around the hole that came into contact with the plastic wood.
Use of plastic wood in the furniture business is labour intensive, especially to smooth the surface of the plastic wood. In addition, plastic wood requires a long period of time to set, resulting in both delays in furniture production and labour intensive steps.